1. Field of the Invention
This invention relates to a data processing apparatus, data processing method and data recording medium on which a data processing program that can be read by a computer is recorded, and more particularly to a data processing apparatus and data processing method that are capable of data exchange with a central processing apparatus, and a data recording medium on which a data processing program for sending and receiving data is recorded
2. Description of the Related Art
Recently, the IEEE1394 standard (properly called “IEEE Std. 1394-1995 IEEE Standard for a High Performance Serial Bus”) has become commonplace as the standard for transmission networks in which several kinds of data processing devices are connected serially by buses and large amounts of data are transmitted at high speed. Also, there is the SBP (Serial Bus Protocol)-2 standard, which is a standard for controlling data processing devices from a central processing apparatus in a system where the central processing apparatus such as a computer or the like, which uses a serial bus that complies to the IEEE1394 standard, is connected with a data processing apparatus (peripheral device) such as a drive. Based on this SBP-2 standard, it is possible to connect a device such as a hard disc drive (HDD), CD-ROM (Compact Disc-Read Only Memory) drive, or DVD-ROM (DVD-Read Only Memory) drive to a personal computer via a serial bus that complies to the IEEE1394 standard, and in this SBP-2 standard the device that sends data is normally called the initiator, and the device that receives data is normally called the target.
Moreover, in the SBP-2 standard, when transmitting data, first the initiator performs a process called login to create a communication path (channel) with the target. Then, after data transmission is finished, a process called logout is executed by the initiator to cut the currently used channel and terminate the connection with the target.
In the case of connecting a data processing apparatus, such as a CD-ROM drive having an easily replaceable recording medium such as a disk, with the central processing apparatus, a control program (normally called the driver program) for performing control is stored in the central processing apparatus in order to control the data processing apparatus from the central processing apparatus, and depending on the type of recording medium that is mounted in the data processing apparatus, the central processing apparatus is typically configured such that it can control the data processing apparatus by properly using a plurality of control programs.
In another form, the control program may be recorded on a recording medium that is mounted in the data processing apparatus itself, and that program is read and executed by the central processing apparatus in order to control the data processing apparatus.
In this case, in the conventional SBP-2 standard mentioned above, when the recording medium, which is mounted in the data processing apparatus and which is recognized by the central processing apparatus, was changed, it was necessary for the central processing apparatus to continuously check the data processing unit after the aforementioned logout process had been executed and the recording medium had been ejected from the data processing apparatus, as to whether or not another recording medium had been newly mounted in the data processing apparatus. In other words, the central processing apparatus repeatedly logged in to the data processing apparatus, checked whether or not a recording medium had been mounted and logged out from the data processing apparatus until another medium was mounted.
However, in the conventional configuration, since a series of processes was performed in very short periods of time until another recording medium was mounted, there was a problem in that the efficiency and speed of performing processing of a data processing apparatus (for example a HDD, etc.) other than the data processing apparatus, in which the recording medium was mounted, decreased.
Moreover, in the case when three or more data processing devices are connected to a single central processing unit, this problem becomes worse.